1,132 research outputs found

    Frequency of Multiple Paternity in the Spiny Dogfish Squalus acanthias in the Western North Atlantic

    Get PDF
    Multiple paternity (MP) has been shown to be widespread in elasmobranch fishes although its prevalence and the number of sires per litter vary considerably among species. In the squaloid shark Squalus acanthias, MP has been reported, but whether it is a common feature of the species\u27 reproductive strategy is unknown. In this study, we determined the frequency of MP in 29 litters of S. acanthias sampled from the lower Chesapeake Bay and coastal Virginia waters, using 7 highly polymorphic nuclear DNA microsatellite loci. Only 5 litters (17% of the total) were genetically polyandrous, with at least 2 sires per litter. Litter size increased with female size but was similar between polyandrous and monandrous females

    Pivotal role of VASP in Arp2/3 complex–mediated actin nucleation, actin branch-formation, and Listeria monocytogenes motility

    Get PDF
    The Listeria monocytogenes ActA protein mediates actin-based motility by recruiting and stimulating the Arp2/3 complex. In vitro, the actin monomer-binding region of ActA is critical for stimulating Arp2/3-dependent actin nucleation; however, this region is dispensable for actin-based motility in cells. Here, we provide genetic and biochemical evidence that vasodilator-stimulated phosphoprotein (VASP) recruitment by ActA can bypass defects in actin monomer-binding. Furthermore, purified VASP enhances the actin-nucleating activity of wild-type ActA and the Arp2/3 complex while also reducing the frequency of actin branch formation. These data suggest that ActA stimulates the Arp2/3 complex by both VASP-dependent and -independent mechanisms that generate distinct populations of actin filaments in the comet tails of L. monocytogenes. The ability of VASP to contribute to actin filament nucleation and to regulate actin filament architecture highlights the central role of VASP in actin-based motility

    CP and related phenomena in the context of Stellar Evolution

    Full text link
    We review the interaction in intermediate and high mass stars between their evolution and magnetic and chemical properties. We describe the theory of Ap-star `fossil' fields, before touching on the expected secular diffusive processes which give rise to evolution of the field. We then present recent results from a spectropolarimetric survey of Herbig Ae/Be stars, showing that magnetic fields of the kind seen on the main-sequence already exist during the pre-main sequence phase, in agreement with fossil field theory, and that the origin of the slow rotation of Ap/Bp stars also lies early in the pre-main sequence evolution; we also present results confirming a lack of stars with fields below a few hundred gauss. We then seek which macroscopic motions compete with atomic diffusion in determining the surface abundances of AmFm stars. While turbulent transport and mass loss, in competition with atomic diffusion, are both able to explain observed surface abundances, the interior abundance distribution is different enough to potentially lead to a test using asterosismology. Finally we review progress on the turbulence-driving and mixing processes in stellar radiative zones.Comment: Proceedings of IAU GA in Rio, JD4 on Ap stars; 10 pages, 7 figure

    Breast conserving surgery in the treatment of breast cancer stage III

    Get PDF
    This study evaluated the ability to perform organ-operation in breast cancer stage III. Highlight 2 similar groups of patients, depending on the extent of the procedure: in the 1st (main) were performed breast conserving surgery (BCS), in the 2nd (control) radical mastectomy (RM) with preservation of the pectoral muscles. It was analyzed overall survival (OS), disease-free survival (DFS); the frequency of postoperative complications and aesthetic results of the treatment. The 3-, 5- and 10-year OS group did not differ significantly and amounted to 80.0 ± 8.0, 87.0 ± 4.6 %; 70.2 ± 9.7, 67.8 ± 6.7 %; 61.4 ± 11.8, 62.2 ± 7.2 %, respectively (p > 0.05). The 3-, 5- and 10-year DFS group did not differ significantly and amounted to 68.1 ± 9.2, 80.7 ± 5.5 %; 58.9 ± 10.9, 67.2 ± 6.6 %; 58.9 ± 10.9, 60.3 ± 7.2 %), respectively (p > 0.05). The frequency of postoperative complications was in the group of BCS 7.7 %, in the group of RM – 6.9 % (p > 0.05). The aesthetic results of the treatment: satisfactory when BCS, unsatisfactory at RM

    Centerscope

    Full text link
    Centerscope, formerly Scope, was published by the Boston University Medical Center "to communicate the concern of the Medical Center for the development and maintenance of improved health care in contemporary society.

    Does mating behaviour affect connectivity in marine fishes? Comparative population genetics of two protogynous groupers (Family Serranidae)

    Get PDF
    Abstract Pelagic larval duration (PLD) has been hypothesized to be the primary predictor of connectivity in marine fishes; however, few studies have examined the effects that adult reproductive behaviour may have on realized dispersal. We assessed gene flow (connectivity) by documenting variation in microsatellites and mitochondrial DNA sequences in two protogynous species of groupers, the aggregate spawning red hind, Epinephelus guttatus, and the single-male, harem-spawning coney, Cephalopholis fulva, to ask whether reproductive strategy affects connectivity. Samples of both species were obtained from waters off three islands (Puerto Rico, St. Thomas and St. Croix) in the Caribbean Sea. Despite the notion that aggregate spawning of red hind may facilitate larval retention, stronger signals of population structure were detected in the haremspawning coney. Heterogeneity and/or inferred barriers, based on microsatellites, involved St. Croix (red hind and coney) and the west coast of Puerto Rico (coney). Heterogeneity and/or inferred barriers, based on mitochondrial DNA, involved St. Croix (coney only). Genetic divergence in both species was stronger for microsatellites than for mitochondrial DNA, suggesting sex-biased dispersal in both species. Longterm migration rates, based on microsatellites, indicated asymmetric gene flow for both species in the same direction as mean surface currents in the region. Red hind had higher levels of variation in microsatellites and lower levels of variation in mitochondrial DNA. Long-term effective size and effective number of breeders were greater for red hind; estimates of h f , a proxy for long-term effective female size, were the same in both species. Patterns of gene flow in both species appear to stem in part from shared aspects of larval and adult biology, local bathymetry and surface current patterns. Differences in connectivity and levels of genetic variation between the species, however, likely stem from differences in behaviour related to reproductive strategy

    Analysis of angiogenesis biomarkers for ramucirumab efficacy in patients with metastatic colorectal cancer from RAISE, a global, randomized, double-blind, phase III study

    Get PDF
    The phase III RAISE trial (NCT01183780) demonstrated that the vascular endothelial growth factor (VEGF) receptor (VEGFR)-2 binding monoclonal antibody ramucirumab plus 5-fluororuracil, leucovorin, and irinotecan (FOLFIRI) significantly improved overall survival (OS) and progression-free survival (PFS) compared with placebo + FOLFIRI as second-line metastatic colorectal cancer (mCRC) treatment. To identify patients who benefit the most from VEGFR-2 blockade, the RAISE trial design included a prospective and comprehensive biomarker program that assessed the association of biomarkers with ramucirumab efficacy outcomes. Plasma and tumor tissue collection was mandatory. Overall, 1072 patients were randomized 1 : 1 to the addition of ramucirumab or placebo to FOLFIRI chemotherapy. Patients were then randomized 1 : 2, for the biomarker program, to marker exploratory (ME) and marker confirmatory (MC) groups. Analyses were carried out using exploratory assays to assess the correlations of baseline marker levels [VEGF-C, VEGF-D, sVEGFR-1, sVEGFR-2, sVEGFR-3 (plasma), and VEGFR-2 (tumor tissue)] with clinical outcomes. Cox regression analyses were carried out for each candidate biomarker with stratification factor adjustment. Biomarker results were available from >80% (n = 894) of patients. Analysis of the ME subset determined a VEGF-D level of 115 pg/ml was appropriate for high/low subgroup analyses. Evaluation of the combined ME + MC populations found that the median OS in the ramucirumab + FOLFIRI arm compared with placebo + FOLFIRI showed an improvement of 2.4 months in the high VEGF-D subgroup [13.9 months (95% CI 12.5–15.6) versus 11.5 months (95% CI 10.1–12.4), respectively], and a decrease of 0.5 month in the low VEGF-D subgroup [12.6 months (95% CI 10.7–14.0) versus 13.1 months (95% CI 11.8–17.0), respectively]. PFS results were consistent with OS. No trends were evident with the other antiangiogenic candidate biomarkers. The RAISE biomarker program identified VEGF-D as a potential predictive biomarker for ramucirumab efficacy in second-line mCRC. Development of an assay appropriate for testing in clinical practice is currently ongoing. NCT01183780

    Invasive Extravillous Trophoblasts Restrict Intracellular Growth and Spread of Listeria monocytogenes

    Get PDF
    Listeria monocytogenes is a facultative intracellular bacterial pathogen that can infect the placenta, a chimeric organ made of maternal and fetal cells. Extravillous trophoblasts (EVT) are specialized fetal cells that invade the uterine implantation site, where they come into direct contact with maternal cells. We have shown previously that EVT are the preferred site of initial placental infection. In this report, we infected primary human EVT with L. monocytogenes. EVT eliminated ∼80% of intracellular bacteria over 24-hours. Bacteria were unable to escape into the cytoplasm and remained confined to vacuolar compartments that became acidified and co-localized with LAMP1, consistent with bacterial degradation in lysosomes. In human placental organ cultures bacterial vacuolar escape rates differed between specific trophoblast subpopulations. The most invasive EVT—those that would be in direct contact with maternal cells in vivo—had lower escape rates than trophoblasts that were surrounded by fetal cells and tissues. Our results suggest that EVT present a bottleneck in the spread of L. monocytogenes from mother to fetus by inhibiting vacuolar escape, and thus intracellular bacterial growth. However, if L. monocytogenes is able to spread beyond EVT it can find a more hospitable environment. Our results elucidate a novel aspect of the maternal-fetal barrier
    • …
    corecore